"Switched On Bach" was even more impressive when you consider that those early Series 900 Moogs had a serious problem with pitch drift. (We had one at #Oberlin Conservatory back in the Seventies.)

Carlos and her producer Rachel Elkind (sp?) could only record a few notes before the oscillators started to drift off tune. So the entire album was cut together (literally) a few notes at a time using razor blades and adhesive tape.